CreditCardConverter Class accepts a Credit Card Number of type String
and strips blanks and "-" if any from it. It also formats the
CreditCardNumber such a blank space separates every four characters.
Blanks and "-" characters are the expected demiliters
that could be used as part of a CreditCardNumber.

getAsString(javax.faces.context.FacesContext context,
javax.faces.component.UIComponent component,
Object value)
Formats the value by inserting space after every four characters
for better readability if they don't already exist.

CONVERSION_ERROR_MESSAGE_ID

The message identifier of the Message to be created if
the conversion fails. The message format string for this
message may optionally include a {0} and
{1} placeholders, which
will be replaced by the object and value.